This invention relates to a carton blank made of sheet material such as corrugated paperboard, a partially formed carton for shipment in flat condition to the packager and a completely erected carton made from the blank for packaging irregularly shaped articles such as partly disassembled bicycles.
The prior art is replete with disclosures of corrugated paperboard cartons designed for this purpose. They all have disadvantages of one kind or another which the design according to the present invention overcomes.
A primary objective of good carton design is to avoid waste as much as possible. This is accomplished by using, for the most part, a piece of sheet material having a rectangular shape and using it in its entirety for making the container blank and forming the container and all its parts without having to cut away certain portions which then become waste, leaving an irregularly shaped blank.
A long high and narrow carton such as is required for packaging a bicycle has inherent weaknesses. Internal strengthening is needed so that the carton and its contents are able to withstand the pressures of stacking and handling by clamp trucks and the like during storage and shipping. Accordingly, internal bracing has been embodied in the carton design for such packaging, usually of the paperboard sheet material which is used for the body of the carton itself, folded into various shapes to form strengthening struts.
At the same time it is desirable to form padding to keep the bicycle parts or other contents of the carton from tilting or migrating inside the container during the shipment. Accordingly, the internal bracing provided is often arranged to perform that function also.
While a standard carton design without the internal bracing and padding has long been made out of a rectangular shape, it is difficult to incorporate into such a rectangle portions and parts which are integral with the carton blank and which can also be arranged to provide the internal bracing and padding necessary, particularly in order to provide bracing and padding in two directions within the box.
Accordingly, most of the prior container designs have used inserts for the strengthening and padding or cushioning parts which are separate from and not integral with the carton blank itself. When such internal strengthening and padding parts have been incorporated into the carton blank as integral parts, the basic carton blank shape is no longer rectangular, therefore causing waste, the bracing and padding does not run in two directions between walls of the cartons or if it does, the bracing or strut columns do not fully extend from wall to wall within the carton.
The carton manufacturer wants to be able to form the carton blank into a collapsible tube which he can ship flat to his customer, the packager, who will then erect the tube-formed blank into, the carton in which he will package his goods. If the carton blank is an irregular shape and particularly if it also requires extra parts as inserts, the, carton manufacturer has problems and complications which he would not have if he could ship a simple rectangular blank which has first been formed with a manufacturers joint into a flattened tube. And his customer, the packager, does not want to have to be bothered with separate inserts which, unless they are fastened to the interior of the erected carton, will drift around inside it.
Accordingly, it is the general object of this invention to provide an economical, i.e., wasteless paperboard carton blank which has integral parts which can be formed into internal strut columns, and pads extending in two different directions fully from wall to wall within the carton as the latter is being erected by the package. Another object is to provide integral locking means by which parts of the blank when folded over with respect to each other to form strut columns may be easily and quickly interlocked so as to remain in place within the carton during its life as a package for its enclosed contents.